video: Add i.MX23/28 framebuffer driver

changes since v2:

- use v3 and v4 for specifying the ip version instead of i.MX23/28.
  This is a better namespace when future versions are added.
- rename mach/fb.h to mach/mxsfb.h

changes since v1:
- Add a LCDC_ prefix to the register names.
- use set/clear registers where appropriate
- protect call to mxsfb_disable_controller() in mxsfb_remove()
  with a (host->enabled) as suggested by Lothar Wassmann

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Shawn Guo <shawn.guo@freescale.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: linux-fbdev@vger.kernel.org

3 files changed, 929 insertions, 0 deletions

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 6bafb51b..e0ea23f 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -2365,6 +2365,15 @@ config FB_JZ4740
 	help
 	  Framebuffer support for the JZ4740 SoC.
 
+config FB_MXS
+	tristate "MXS LCD framebuffer support"
+	depends on FB && ARCH_MXS
+	select FB_CFB_FILLRECT
+	select FB_CFB_COPYAREA
+	select FB_CFB_IMAGEBLIT
+	help
+	  Framebuffer support for the MXS SoC.
+
 source "drivers/video/omap/Kconfig"
 source "drivers/video/omap2/Kconfig"
 
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index 8c8fabd..9a096ae 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -153,6 +153,7 @@ obj-$(CONFIG_FB_BFIN_T350MCQB)	  += bfin-t350mcqb-fb.o
 obj-$(CONFIG_FB_BFIN_7393)        += bfin_adv7393fb.o
 obj-$(CONFIG_FB_MX3)		  += mx3fb.o
 obj-$(CONFIG_FB_DA8XX)		  += da8xx-fb.o
+obj-$(CONFIG_FB_MXS)		  += mxsfb.o
 
 # the test framebuffer is last
 obj-$(CONFIG_FB_VIRTUAL)          += vfb.o
diff --git a/drivers/video/mxsfb.c b/drivers/video/mxsfb.c
new file mode 100644
index 0000000..7d02848
--- /dev/null
+++ b/drivers/video/mxsfb.c
@@ -0,0 +1,919 @@
+/*
+ * Copyright (C) 2010 Juergen Beisert, Pengutronix
+ *
+ * This code is based on:
+ * Author: Vitaly Wool <vital@embeddedalley.com>
+ *
+ * Copyright 2008-2009 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#define DRIVER_NAME "mxsfb"
+
+/**
+ * @file
+ * @brief LCDIF driver for i.MX23 and i.MX28
+ *
+ * The LCDIF support four modes of operation
+ * - MPU interface (to drive smart displays) -> not supported yet
+ * - VSYNC interface (like MPU interface plus Vsync) -> not supported yet
+ * - Dotclock interface (to drive LC displays with RGB data and sync signals)
+ * - DVI (to drive ITU-R BT656)  -> not supported yet
+ *
+ * This driver depends on a correct setup of the pins used for this purpose
+ * (platform specific).
+ *
+ * For the developer: Don't forget to set the data bus width to the display
+ * in the imx_fb_videomode structure. You will else end up with ugly colours.
+ * If you fight against jitter you can vary the clock delay. This is a feature
+ * of the i.MX28 and you can vary it between 2 ns ... 8 ns in 2 ns steps. Give
+ * the required value in the imx_fb_videomode structure.
+ */
+
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+#include <mach/mxsfb.h>
+
+#define REG_SET	4
+#define REG_CLR	8
+
+#define LCDC_CTRL			0x00
+#define LCDC_CTRL1			0x10
+#define LCDC_V4_CTRL2			0x20
+#define LCDC_V3_TRANSFER_COUNT		0x20
+#define LCDC_V4_TRANSFER_COUNT		0x30
+#define LCDC_V4_CUR_BUF			0x40
+#define LCDC_V4_NEXT_BUF		0x50
+#define LCDC_V3_CUR_BUF			0x30
+#define LCDC_V3_NEXT_BUF		0x40
+#define LCDC_TIMING			0x60
+#define LCDC_VDCTRL0			0x70
+#define LCDC_VDCTRL1			0x80
+#define LCDC_VDCTRL2			0x90
+#define LCDC_VDCTRL3			0xa0
+#define LCDC_VDCTRL4			0xb0
+#define LCDC_DVICTRL0			0xc0
+#define LCDC_DVICTRL1			0xd0
+#define LCDC_DVICTRL2			0xe0
+#define LCDC_DVICTRL3			0xf0
+#define LCDC_DVICTRL4			0x100
+#define LCDC_V4_DATA			0x180
+#define LCDC_V3_DATA			0x1b0
+#define LCDC_V4_DEBUG0			0x1d0
+#define LCDC_V3_DEBUG0			0x1f0
+
+#define CTRL_SFTRST			(1 << 31)
+#define CTRL_CLKGATE			(1 << 30)
+#define CTRL_BYPASS_COUNT		(1 << 19)
+#define CTRL_VSYNC_MODE			(1 << 18)
+#define CTRL_DOTCLK_MODE		(1 << 17)
+#define CTRL_DATA_SELECT		(1 << 16)
+#define CTRL_SET_BUS_WIDTH(x)		(((x) & 0x3) << 10)
+#define CTRL_GET_BUS_WIDTH(x)		(((x) >> 10) & 0x3)
+#define CTRL_SET_WORD_LENGTH(x)		(((x) & 0x3) << 8)
+#define CTRL_GET_WORD_LENGTH(x)		(((x) >> 8) & 0x3)
+#define CTRL_MASTER			(1 << 5)
+#define CTRL_DF16			(1 << 3)
+#define CTRL_DF18			(1 << 2)
+#define CTRL_DF24			(1 << 1)
+#define CTRL_RUN			(1 << 0)
+
+#define CTRL1_FIFO_CLEAR		(1 << 21)
+#define CTRL1_SET_BYTE_PACKAGING(x)	(((x) & 0xf) << 16)
+#define CTRL1_GET_BYTE_PACKAGING(x)	(((x) >> 16) & 0xf)
+
+#define TRANSFER_COUNT_SET_VCOUNT(x)	(((x) & 0xffff) << 16)
+#define TRANSFER_COUNT_GET_VCOUNT(x)	(((x) >> 16) & 0xffff)
+#define TRANSFER_COUNT_SET_HCOUNT(x)	((x) & 0xffff)
+#define TRANSFER_COUNT_GET_HCOUNT(x)	((x) & 0xffff)
+
+
+#define VDCTRL0_ENABLE_PRESENT		(1 << 28)
+#define VDCTRL0_VSYNC_ACT_HIGH		(1 << 27)
+#define VDCTRL0_HSYNC_ACT_HIGH		(1 << 26)
+#define VDCTRL0_DOTCLK_ACT_FAILING	(1 << 25)
+#define VDCTRL0_ENABLE_ACT_HIGH		(1 << 24)
+#define VDCTRL0_VSYNC_PERIOD_UNIT	(1 << 21)
+#define VDCTRL0_VSYNC_PULSE_WIDTH_UNIT	(1 << 20)
+#define VDCTRL0_HALF_LINE		(1 << 19)
+#define VDCTRL0_HALF_LINE_MODE		(1 << 18)
+#define VDCTRL0_SET_VSYNC_PULSE_WIDTH(x) ((x) & 0x3ffff)
+#define VDCTRL0_GET_VSYNC_PULSE_WIDTH(x) ((x) & 0x3ffff)
+
+#define VDCTRL2_SET_HSYNC_PERIOD(x)	((x) & 0x3ffff)
+#define VDCTRL2_GET_HSYNC_PERIOD(x)	((x) & 0x3ffff)
+
+#define VDCTRL3_MUX_SYNC_SIGNALS	(1 << 29)
+#define VDCTRL3_VSYNC_ONLY		(1 << 28)
+#define SET_HOR_WAIT_CNT(x)		(((x) & 0xfff) << 16)
+#define GET_HOR_WAIT_CNT(x)		(((x) >> 16) & 0xfff)
+#define SET_VERT_WAIT_CNT(x)		((x) & 0xffff)
+#define GET_VERT_WAIT_CNT(x)		((x) & 0xffff)
+
+#define VDCTRL4_SET_DOTCLK_DLY(x)	(((x) & 0x7) << 29) /* v4 only */
+#define VDCTRL4_GET_DOTCLK_DLY(x)	(((x) >> 29) & 0x7) /* v4 only */
+#define VDCTRL4_SYNC_SIGNALS_ON		(1 << 18)
+#define SET_DOTCLK_H_VALID_DATA_CNT(x)	((x) & 0x3ffff)
+
+#define DEBUG0_HSYNC			(1 < 26)
+#define DEBUG0_VSYNC			(1 < 25)
+
+#define MIN_XRES			120
+#define MIN_YRES			120
+
+#define RED 0
+#define GREEN 1
+#define BLUE 2
+#define TRANSP 3
+
+enum mxsfb_devtype {
+	MXSFB_V3,
+	MXSFB_V4,
+};
+
+/* CPU dependent register offsets */
+struct mxsfb_devdata {
+	unsigned transfer_count;
+	unsigned cur_buf;
+	unsigned next_buf;
+	unsigned debug0;
+	unsigned hs_wdth_mask;
+	unsigned hs_wdth_shift;
+	unsigned ipversion;
+};
+
+struct mxsfb_info {
+	struct fb_info fb_info;
+	struct platform_device *pdev;
+	struct clk *clk;
+	void __iomem *base;	/* registers */
+	unsigned allocated_size;
+	int enabled;
+	unsigned ld_intf_width;
+	unsigned dotclk_delay;
+	const struct mxsfb_devdata *devdata;
+	int mapped;
+};
+
+#define mxsfb_is_v3(host) (host->devdata->ipversion == 3)
+#define mxsfb_is_v4(host) (host->devdata->ipversion == 4)
+
+static const struct mxsfb_devdata mxsfb_devdata[] = {
+	[MXSFB_V3] = {
+		.transfer_count = LCDC_V3_TRANSFER_COUNT,
+		.cur_buf = LCDC_V3_CUR_BUF,
+		.next_buf = LCDC_V3_NEXT_BUF,
+		.debug0 = LCDC_V3_DEBUG0,
+		.hs_wdth_mask = 0xff,
+		.hs_wdth_shift = 24,
+		.ipversion = 3,
+	},
+	[MXSFB_V4] = {
+		.transfer_count = LCDC_V4_TRANSFER_COUNT,
+		.cur_buf = LCDC_V4_CUR_BUF,
+		.next_buf = LCDC_V4_NEXT_BUF,
+		.debug0 = LCDC_V4_DEBUG0,
+		.hs_wdth_mask = 0x3fff,
+		.hs_wdth_shift = 18,
+		.ipversion = 4,
+	},
+};
+
+#define to_imxfb_host(x) (container_of(x, struct mxsfb_info, fb_info))
+
+/* mask and shift depends on architecture */
+static inline u32 set_hsync_pulse_width(struct mxsfb_info *host, unsigned val)
+{
+	return (val & host->devdata->hs_wdth_mask) <<
+		host->devdata->hs_wdth_shift;
+}
+
+static inline u32 get_hsync_pulse_width(struct mxsfb_info *host, unsigned val)
+{
+	return (val >> host->devdata->hs_wdth_shift) &
+		host->devdata->hs_wdth_mask;
+}
+
+static const struct fb_bitfield def_rgb565[] = {
+	[RED] = {
+		.offset = 11,
+		.length = 5,
+	},
+	[GREEN] = {
+		.offset = 5,
+		.length = 6,
+	},
+	[BLUE] = {
+		.offset = 0,
+		.length = 5,
+	},
+	[TRANSP] = {	/* no support for transparency */
+		.length = 0,
+	}
+};
+
+static const struct fb_bitfield def_rgb666[] = {
+	[RED] = {
+		.offset = 16,
+		.length = 6,
+	},
+	[GREEN] = {
+		.offset = 8,
+		.length = 6,
+	},
+	[BLUE] = {
+		.offset = 0,
+		.length = 6,
+	},
+	[TRANSP] = {	/* no support for transparency */
+		.length = 0,
+	}
+};
+
+static const struct fb_bitfield def_rgb888[] = {
+	[RED] = {
+		.offset = 16,
+		.length = 8,
+	},
+	[GREEN] = {
+		.offset = 8,
+		.length = 8,
+	},
+	[BLUE] = {
+		.offset = 0,
+		.length = 8,
+	},
+	[TRANSP] = {	/* no support for transparency */
+		.length = 0,
+	}
+};
+
+static inline unsigned chan_to_field(unsigned chan, struct fb_bitfield *bf)
+{
+	chan &= 0xffff;
+	chan >>= 16 - bf->length;
+	return chan << bf->offset;
+}
+
+static int mxsfb_check_var(struct fb_var_screeninfo *var,
+		struct fb_info *fb_info)
+{
+	struct mxsfb_info *host = to_imxfb_host(fb_info);
+	const struct fb_bitfield *rgb = NULL;
+
+	if (var->xres < MIN_XRES)
+		var->xres = MIN_XRES;
+	if (var->yres < MIN_YRES)
+		var->yres = MIN_YRES;
+
+	var->xres_virtual = var->xres;
+
+	var->yres_virtual = var->yres;
+
+	switch (var->bits_per_pixel) {
+	case 16:
+		/* always expect RGB 565 */
+		rgb = def_rgb565;
+		break;
+	case 32:
+		switch (host->ld_intf_width) {
+		case STMLCDIF_8BIT:
+			pr_debug("Unsupported LCD bus width mapping\n");
+			break;
+		case STMLCDIF_16BIT:
+		case STMLCDIF_18BIT:
+			/* 24 bit to 18 bit mapping */
+			rgb = def_rgb666;
+			break;
+		case STMLCDIF_24BIT:
+			/* real 24 bit */
+			rgb = def_rgb888;
+			break;
+		}
+		break;
+	default:
+		pr_debug("Unsupported colour depth: %u\n", var->bits_per_pixel);
+		return -EINVAL;
+	}
+
+	/*
+	 * Copy the RGB parameters for this display
+	 * from the machine specific parameters.
+	 */
+	var->red    = rgb[RED];
+	var->green  = rgb[GREEN];
+	var->blue   = rgb[BLUE];
+	var->transp = rgb[TRANSP];
+
+	return 0;
+}
+
+static void mxsfb_enable_controller(struct fb_info *fb_info)
+{
+	struct mxsfb_info *host = to_imxfb_host(fb_info);
+	u32 reg;
+
+	dev_dbg(&host->pdev->dev, "%s\n", __func__);
+
+	clk_enable(host->clk);
+	clk_set_rate(host->clk, PICOS2KHZ(fb_info->var.pixclock) * 1000U);
+
+	/* if it was disabled, re-enable the mode again */
+	writel(CTRL_DOTCLK_MODE, host->base + LCDC_CTRL + REG_SET);
+
+	/* enable the SYNC signals first, then the DMA engine */
+	reg = readl(host->base + LCDC_VDCTRL4);
+	reg |= VDCTRL4_SYNC_SIGNALS_ON;
+	writel(reg, host->base + LCDC_VDCTRL4);
+
+	writel(CTRL_RUN, host->base + LCDC_CTRL + REG_SET);
+
+	host->enabled = 1;
+}
+
+static void mxsfb_disable_controller(struct fb_info *fb_info)
+{
+	struct mxsfb_info *host = to_imxfb_host(fb_info);
+	unsigned loop;
+	u32 reg;
+
+	dev_dbg(&host->pdev->dev, "%s\n", __func__);
+
+	/*
+	 * Even if we disable the controller here, it will still continue
+	 * until its FIFOs are running out of data
+	 */
+	writel(CTRL_DOTCLK_MODE, host->base + LCDC_CTRL + REG_CLR);
+
+	loop = 1000;
+	while (loop) {
+		reg = readl(host->base + LCDC_CTRL);
+		if (!(reg & CTRL_RUN))
+			break;
+		loop--;
+	}
+
+	writel(VDCTRL4_SYNC_SIGNALS_ON, host->base + LCDC_VDCTRL4 + REG_CLR);
+
+	clk_disable(host->clk);
+
+	host->enabled = 0;
+}
+
+static int mxsfb_set_par(struct fb_info *fb_info)
+{
+	struct mxsfb_info *host = to_imxfb_host(fb_info);
+	u32 ctrl, vdctrl0, vdctrl4;
+	int line_size, fb_size;
+	int reenable = 0;
+
+	line_size =  fb_info->var.xres * (fb_info->var.bits_per_pixel >> 3);
+	fb_size = fb_info->var.yres_virtual * line_size;
+
+	if (fb_size > fb_info->fix.smem_len)
+		return -ENOMEM;
+
+	fb_info->fix.line_length = line_size;
+
+	/*
+	 * It seems, you can't re-program the controller if it is still running.
+	 * This may lead into shifted pictures (FIFO issue?).
+	 * So, first stop the controller and drain its FIFOs
+	 */
+	if (host->enabled) {
+		reenable = 1;
+		mxsfb_disable_controller(fb_info);
+	}
+
+	/* clear the FIFOs */
+	writel(CTRL1_FIFO_CLEAR, host->base + LCDC_CTRL1 + REG_SET);
+
+	ctrl = CTRL_BYPASS_COUNT | CTRL_MASTER |
+		CTRL_SET_BUS_WIDTH(host->ld_intf_width);;
+
+	switch (fb_info->var.bits_per_pixel) {
+	case 16:
+		dev_dbg(&host->pdev->dev, "Setting up RGB565 mode\n");
+		ctrl |= CTRL_SET_WORD_LENGTH(0);
+		writel(CTRL1_SET_BYTE_PACKAGING(0xf), host->base + LCDC_CTRL1);
+		break;
+	case 32:
+		dev_dbg(&host->pdev->dev, "Setting up RGB888/666 mode\n");
+		ctrl |= CTRL_SET_WORD_LENGTH(3);
+		switch (host->ld_intf_width) {
+		case STMLCDIF_8BIT:
+			dev_dbg(&host->pdev->dev,
+					"Unsupported LCD bus width mapping\n");
+			return -EINVAL;
+		case STMLCDIF_16BIT:
+		case STMLCDIF_18BIT:
+			/* 24 bit to 18 bit mapping */
+			ctrl |= CTRL_DF24; /* ignore the upper 2 bits in
+					    *  each colour component
+					    */
+			break;
+		case STMLCDIF_24BIT:
+			/* real 24 bit */
+			break;
+		}
+		/* do not use packed pixels = one pixel per word instead */
+		writel(CTRL1_SET_BYTE_PACKAGING(0x7), host->base + LCDC_CTRL1);
+		break;
+	default:
+		dev_dbg(&host->pdev->dev, "Unhandled color depth of %u\n",
+				fb_info->var.bits_per_pixel);
+		return -EINVAL;
+	}
+
+	writel(ctrl, host->base + LCDC_CTRL);
+
+	writel(TRANSFER_COUNT_SET_VCOUNT(fb_info->var.yres) |
+			TRANSFER_COUNT_SET_HCOUNT(fb_info->var.xres),
+			host->base + host->devdata->transfer_count);
+
+	vdctrl0 = VDCTRL0_ENABLE_PRESENT |	/* always in DOTCLOCK mode */
+		VDCTRL0_VSYNC_PERIOD_UNIT |
+		VDCTRL0_VSYNC_PULSE_WIDTH_UNIT |
+		VDCTRL0_SET_VSYNC_PULSE_WIDTH(fb_info->var.vsync_len);
+	if (fb_info->var.sync & FB_SYNC_HOR_HIGH_ACT)
+		vdctrl0 |= VDCTRL0_HSYNC_ACT_HIGH;
+	if (fb_info->var.sync & FB_SYNC_VERT_HIGH_ACT)
+		vdctrl0 |= VDCTRL0_VSYNC_ACT_HIGH;
+	if (fb_info->var.sync & FB_SYNC_DATA_ENABLE_HIGH_ACT)
+		vdctrl0 |= VDCTRL0_ENABLE_ACT_HIGH;
+	if (fb_info->var.sync & FB_SYNC_DOTCLK_FAILING_ACT)
+		vdctrl0 |= VDCTRL0_DOTCLK_ACT_FAILING;
+
+	writel(vdctrl0, host->base + LCDC_VDCTRL0);
+
+	/* frame length in lines */
+	writel(fb_info->var.upper_margin + fb_info->var.vsync_len +
+		fb_info->var.lower_margin + fb_info->var.yres,
+		host->base + LCDC_VDCTRL1);
+
+	/* line length in units of clocks or pixels */
+	writel(set_hsync_pulse_width(host, fb_info->var.hsync_len) |
+		VDCTRL2_SET_HSYNC_PERIOD(fb_info->var.left_margin +
+		fb_info->var.hsync_len + fb_info->var.right_margin +
+		fb_info->var.xres),
+		host->base + LCDC_VDCTRL2);
+
+	writel(SET_HOR_WAIT_CNT(fb_info->var.left_margin +
+		fb_info->var.hsync_len) |
+		SET_VERT_WAIT_CNT(fb_info->var.upper_margin +
+			fb_info->var.vsync_len),
+		host->base + LCDC_VDCTRL3);
+
+	vdctrl4 = SET_DOTCLK_H_VALID_DATA_CNT(fb_info->var.xres);
+	if (mxsfb_is_v4(host))
+		vdctrl4 |= VDCTRL4_SET_DOTCLK_DLY(host->dotclk_delay);
+	writel(vdctrl4, host->base + LCDC_VDCTRL4);
+
+	writel(fb_info->fix.smem_start +
+			fb_info->fix.line_length * fb_info->var.yoffset,
+			host->base + host->devdata->next_buf);
+
+	if (reenable)
+		mxsfb_enable_controller(fb_info);
+
+	return 0;
+}
+
+static int mxsfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
+		u_int transp, struct fb_info *fb_info)
+{
+	unsigned int val;
+	int ret = -EINVAL;
+
+	/*
+	 * If greyscale is true, then we convert the RGB value
+	 * to greyscale no matter what visual we are using.
+	 */
+	if (fb_info->var.grayscale)
+		red = green = blue = (19595 * red + 38470 * green +
+					7471 * blue) >> 16;
+
+	switch (fb_info->fix.visual) {
+	case FB_VISUAL_TRUECOLOR:
+		/*
+		 * 12 or 16-bit True Colour.  We encode the RGB value
+		 * according to the RGB bitfield information.
+		 */
+		if (regno < 16) {
+			u32 *pal = fb_info->pseudo_palette;
+
+			val  = chan_to_field(red, &fb_info->var.red);
+			val |= chan_to_field(green, &fb_info->var.green);
+			val |= chan_to_field(blue, &fb_info->var.blue);
+
+			pal[regno] = val;
+			ret = 0;
+		}
+		break;
+
+	case FB_VISUAL_STATIC_PSEUDOCOLOR:
+	case FB_VISUAL_PSEUDOCOLOR:
+		break;
+	}
+
+	return ret;
+}
+
+static int mxsfb_blank(int blank, struct fb_info *fb_info)
+{
+	struct mxsfb_info *host = to_imxfb_host(fb_info);
+
+	switch (blank) {
+	case FB_BLANK_POWERDOWN:
+	case FB_BLANK_VSYNC_SUSPEND:
+	case FB_BLANK_HSYNC_SUSPEND:
+	case FB_BLANK_NORMAL:
+		if (host->enabled)
+			mxsfb_disable_controller(fb_info);
+		break;
+
+	case FB_BLANK_UNBLANK:
+		if (!host->enabled)
+			mxsfb_enable_controller(fb_info);
+		break;
+	}
+	return 0;
+}
+
+static int mxsfb_pan_display(struct fb_var_screeninfo *var,
+		struct fb_info *fb_info)
+{
+	struct mxsfb_info *host = to_imxfb_host(fb_info);
+	unsigned offset;
+
+	if (var->xoffset != 0)
+		return -EINVAL;
+
+	offset = fb_info->fix.line_length * var->yoffset;
+
+	/* update on next VSYNC */
+	writel(fb_info->fix.smem_start + offset,
+			host->base + host->devdata->next_buf);
+
+	return 0;
+}
+
+static struct fb_ops mxsfb_ops = {
+	.owner = THIS_MODULE,
+	.fb_check_var = mxsfb_check_var,
+	.fb_set_par = mxsfb_set_par,
+	.fb_setcolreg = mxsfb_setcolreg,
+	.fb_blank = mxsfb_blank,
+	.fb_pan_display = mxsfb_pan_display,
+	.fb_fillrect = cfb_fillrect,
+	.fb_copyarea = cfb_copyarea,
+	.fb_imageblit = cfb_imageblit,
+};
+
+static int __devinit mxsfb_restore_mode(struct mxsfb_info *host)
+{
+	struct fb_info *fb_info = &host->fb_info;
+	unsigned line_count;
+	unsigned period;
+	unsigned long pa, fbsize;
+	int bits_per_pixel, ofs;
+	u32 transfer_count, vdctrl0, vdctrl2, vdctrl3, vdctrl4, ctrl;
+	struct fb_videomode vmode;
+
+	/* Only restore the mode when the controller is running */
+	ctrl = readl(host->base + LCDC_CTRL);
+	if (!(ctrl & CTRL_RUN))
+		return -EINVAL;
+
+	vdctrl0 = readl(host->base + LCDC_VDCTRL0);
+	vdctrl2 = readl(host->base + LCDC_VDCTRL2);
+	vdctrl3 = readl(host->base + LCDC_VDCTRL3);
+	vdctrl4 = readl(host->base + LCDC_VDCTRL4);
+
+	transfer_count = readl(host->base + host->devdata->transfer_count);
+
+	vmode.xres = TRANSFER_COUNT_GET_HCOUNT(transfer_count);
+	vmode.yres = TRANSFER_COUNT_GET_VCOUNT(transfer_count);
+
+	switch (CTRL_GET_WORD_LENGTH(ctrl)) {
+	case 0:
+		bits_per_pixel = 16;
+		break;
+	case 3:
+		bits_per_pixel = 32;
+	case 1:
+	default:
+		return -EINVAL;
+	}
+
+	fb_info->var.bits_per_pixel = bits_per_pixel;
+
+	vmode.pixclock = KHZ2PICOS(clk_get_rate(host->clk) / 1000U);
+	vmode.hsync_len = get_hsync_pulse_width(host, vdctrl2);
+	vmode.left_margin = GET_HOR_WAIT_CNT(vdctrl3) - vmode.hsync_len;
+	vmode.right_margin = VDCTRL2_GET_HSYNC_PERIOD(vdctrl2) - vmode.hsync_len -
+		vmode.left_margin - vmode.xres;
+	vmode.vsync_len = VDCTRL0_GET_VSYNC_PULSE_WIDTH(vdctrl0);
+	period = readl(host->base + LCDC_VDCTRL1);
+	vmode.upper_margin = GET_VERT_WAIT_CNT(vdctrl3) - vmode.vsync_len;
+	vmode.lower_margin = period - vmode.vsync_len - vmode.upper_margin - vmode.yres;
+
+	vmode.vmode = FB_VMODE_NONINTERLACED;
+
+	vmode.sync = 0;
+	if (vdctrl0 & VDCTRL0_HSYNC_ACT_HIGH)
+		vmode.sync |= FB_SYNC_HOR_HIGH_ACT;
+	if (vdctrl0 & VDCTRL0_VSYNC_ACT_HIGH)
+		vmode.sync |= FB_SYNC_VERT_HIGH_ACT;
+
+	pr_debug("Reconstructed video mode:\n");
+	pr_debug("%dx%d, hsync: %u left: %u, right: %u, vsync: %u, upper: %u, lower: %u\n",
+			vmode.xres, vmode.yres,
+			vmode.hsync_len, vmode.left_margin, vmode.right_margin,
+			vmode.vsync_len, vmode.upper_margin, vmode.lower_margin);
+	pr_debug("pixclk: %ldkHz\n", PICOS2KHZ(vmode.pixclock));
+
+	fb_add_videomode(&vmode, &fb_info->modelist);
+
+	host->ld_intf_width = CTRL_GET_BUS_WIDTH(ctrl);
+	host->dotclk_delay = VDCTRL4_GET_DOTCLK_DLY(vdctrl4);
+
+	fb_info->fix.line_length = vmode.xres * (bits_per_pixel >> 3);
+
+	pa = readl(host->base + host->devdata->cur_buf);
+	fbsize = fb_info->fix.line_length * vmode.yres;
+	if (pa < fb_info->fix.smem_start)
+		return -EINVAL;
+	if (pa + fbsize > fb_info->fix.smem_start + fb_info->fix.smem_len)
+		return -EINVAL;
+	ofs = pa - fb_info->fix.smem_start;
+	if (ofs) {
+		memmove(fb_info->screen_base, fb_info->screen_base + ofs, fbsize);
+		writel(fb_info->fix.smem_start, host->base + host->devdata->next_buf);
+	}
+
+	line_count = fb_info->fix.smem_len / fb_info->fix.line_length;
+	fb_info->fix.ypanstep = 1;
+
+	clk_enable(host->clk);
+	host->enabled = 1;
+
+	return 0;
+}
+
+static int __devinit mxsfb_init_fbinfo(struct mxsfb_info *host)
+{
+	struct fb_info *fb_info = &host->fb_info;
+	struct fb_var_screeninfo *var = &fb_info->var;
+	struct mxsfb_platform_data *pdata = host->pdev->dev.platform_data;
+	dma_addr_t fb_phys;
+	void *fb_virt;
+	unsigned fb_size = pdata->fb_size;
+
+	fb_info->fbops = &mxsfb_ops;
+	fb_info->flags = FBINFO_FLAG_DEFAULT | FBINFO_READS_FAST;
+	strlcpy(fb_info->fix.id, "mxs", sizeof(fb_info->fix.id));
+	fb_info->fix.type = FB_TYPE_PACKED_PIXELS;
+	fb_info->fix.ypanstep = 1;
+	fb_info->fix.visual = FB_VISUAL_TRUECOLOR,
+	fb_info->fix.accel = FB_ACCEL_NONE;
+
+	var->bits_per_pixel = pdata->default_bpp ? pdata->default_bpp : 16;
+	var->nonstd = 0;
+	var->activate = FB_ACTIVATE_NOW;
+	var->accel_flags = 0;
+	var->vmode = FB_VMODE_NONINTERLACED;
+
+	host->dotclk_delay = pdata->dotclk_delay;
+	host->ld_intf_width = pdata->ld_intf_width;
+
+	/* Memory allocation for framebuffer */
+	if (pdata->fb_phys) {
+		if (!fb_size)
+			return -EINVAL;
+
+		fb_phys = pdata->fb_phys;
+
+		if (!request_mem_region(fb_phys, fb_size, host->pdev->name))
+			return -ENOMEM;
+
+		fb_virt = ioremap(fb_phys, fb_size);
+		if (!fb_virt) {
+			release_mem_region(fb_phys, fb_size);
+			return -ENOMEM;
+		}
+		host->mapped = 1;
+	} else {
+		if (!fb_size)
+			fb_size = SZ_2M; /* default */
+		fb_virt = alloc_pages_exact(fb_size, GFP_DMA);
+		if (!fb_virt)
+			return -ENOMEM;
+
+		fb_phys = virt_to_phys(fb_virt);
+	}
+
+	fb_info->fix.smem_start = fb_phys;
+	fb_info->screen_base = fb_virt;
+	fb_info->screen_size = fb_info->fix.smem_len = fb_size;
+
+	if (mxsfb_restore_mode(host))
+		memset(fb_virt, 0, fb_size);
+
+	return 0;
+}
+
+static void __devexit mxsfb_free_videomem(struct mxsfb_info *host)
+{
+	struct fb_info *fb_info = &host->fb_info;
+
+	if (host->mapped) {
+		iounmap(fb_info->screen_base);
+		release_mem_region(fb_info->fix.smem_start,
+				fb_info->screen_size);
+	} else {
+		free_pages_exact(fb_info->screen_base, fb_info->fix.smem_len);
+	}
+}
+
+static int __devinit mxsfb_probe(struct platform_device *pdev)
+{
+	struct mxsfb_platform_data *pdata = pdev->dev.platform_data;
+	struct resource *res;
+	struct mxsfb_info *host;
+	struct fb_info *fb_info;
+	struct fb_modelist *modelist;
+	int i, ret;
+
+	if (!pdata) {
+		dev_err(&pdev->dev, "No platformdata. Giving up\n");
+		return -ENODEV;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "Cannot get memory IO resource\n");
+		return -ENODEV;
+	}
+
+	if (!request_mem_region(res->start, resource_size(res), pdev->name))
+		return -EBUSY;
+
+	fb_info = framebuffer_alloc(sizeof(struct mxsfb_info), &pdev->dev);
+	if (!fb_info) {
+		dev_err(&pdev->dev, "Failed to allocate fbdev\n");
+		ret = -ENOMEM;
+		goto error_alloc_info;
+	}
+
+	host = to_imxfb_host(fb_info);
+
+	host->base = ioremap(res->start, resource_size(res));
+	if (!host->base) {
+		dev_err(&pdev->dev, "ioremap failed\n");
+		ret = -ENOMEM;
+		goto error_ioremap;
+	}
+
+	host->pdev = pdev;
+	platform_set_drvdata(pdev, host);
+
+	host->devdata = &mxsfb_devdata[pdev->id_entry->driver_data];
+
+	host->clk = clk_get(&host->pdev->dev, NULL);
+	if (IS_ERR(host->clk)) {
+		ret = PTR_ERR(host->clk);
+		goto error_getclock;
+	}
+
+	fb_info->pseudo_palette = kmalloc(sizeof(u32) * 16, GFP_KERNEL);
+	if (!fb_info->pseudo_palette) {
+		ret = -ENOMEM;
+		goto error_pseudo_pallette;
+	}
+
+	INIT_LIST_HEAD(&fb_info->modelist);
+
+	ret = mxsfb_init_fbinfo(host);
+	if (ret != 0)
+		goto error_init_fb;
+
+	for (i = 0; i < pdata->mode_count; i++)
+		fb_add_videomode(&pdata->mode_list[i], &fb_info->modelist);
+
+	modelist = list_first_entry(&fb_info->modelist,
+			struct fb_modelist, list);
+	fb_videomode_to_var(&fb_info->var, &modelist->mode);
+
+	/* init the color fields */
+	mxsfb_check_var(&fb_info->var, fb_info);
+
+	platform_set_drvdata(pdev, fb_info);
+
+	ret = register_framebuffer(fb_info);
+	if (ret != 0) {
+		dev_err(&pdev->dev,"Failed to register framebuffer\n");
+		goto error_register;
+	}
+
+	if (!host->enabled) {
+		writel(0, host->base + LCDC_CTRL);
+		mxsfb_set_par(fb_info);
+		mxsfb_enable_controller(fb_info);
+	}
+
+	dev_info(&pdev->dev, "initialized\n");
+
+	return 0;
+
+error_register:
+	if (host->enabled)
+		clk_disable(host->clk);
+	fb_destroy_modelist(&fb_info->modelist);
+error_init_fb:
+	kfree(fb_info->pseudo_palette);
+error_pseudo_pallette:
+	clk_put(host->clk);
+error_getclock:
+	iounmap(host->base);
+error_ioremap:
+	framebuffer_release(fb_info);
+error_alloc_info:
+	release_mem_region(res->start, resource_size(res));
+
+	return ret;
+}
+
+static int __devexit mxsfb_remove(struct platform_device *pdev)
+{
+	struct fb_info *fb_info = platform_get_drvdata(pdev);
+	struct mxsfb_info *host = to_imxfb_host(fb_info);
+	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	if (host->enabled)
+		mxsfb_disable_controller(fb_info);
+
+	unregister_framebuffer(fb_info);
+	kfree(fb_info->pseudo_palette);
+	mxsfb_free_videomem(host);
+	iounmap(host->base);
+	clk_put(host->clk);
+
+	framebuffer_release(fb_info);
+	release_mem_region(res->start, resource_size(res));
+
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static struct platform_device_id mxsfb_devtype[] = {
+	{
+		.name = "imx23-fb",
+		.driver_data = MXSFB_V3,
+	}, {
+		.name = "imx28-fb",
+		.driver_data = MXSFB_V4,
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(platform, mxsfb_devtype);
+
+static struct platform_driver mxsfb_driver = {
+	.probe = mxsfb_probe,
+	.remove = __devexit_p(mxsfb_remove),
+	.id_table = mxsfb_devtype,
+	.driver = {
+		   .name = DRIVER_NAME,
+	},
+};
+
+static int __init mxsfb_init(void)
+{
+	return platform_driver_register(&mxsfb_driver);
+}
+
+static void __exit mxsfb_exit(void)
+{
+	platform_driver_unregister(&mxsfb_driver);
+}
+
+module_init(mxsfb_init);
+module_exit(mxsfb_exit);
+
+MODULE_DESCRIPTION("Freescale mxs framebuffer driver");
+MODULE_AUTHOR("Sascha Hauer, Pengutronix");
+MODULE_LICENSE("GPL");